Article

Macrophage infiltration to the injury site during the acute response
to traumatic spinal cord injury (SCI) is not uniform. Macrophage phenotype has
been characterized as either proinflammatory (M1) or anti-inflammatory (M2).
Results of animal studies suggest that M1 or M2 dominance at the site of injury
relates to spontaneous recovery after SCI. OBJECTIVE: To investigate whether the
phenotype of circulating macrophage precursors-monocytes (MO) is altered in the
acute phase of SCI and corresponds to circulating inflammatory cytokines.
STUDY
DESIGN: A prospective observational cohort study. SETTING: A single academic
medical center in Pennsylvania. PATIENTS: A cohort of 27 subjects with complete
or incomplete traumatic SCI enrolled within 7 days after SCI injury. METHODS: The
MO phenotype was defined within the first week after SCI by using flow cytometry
and was compared with that of historic uninjured controls. Concentrations of 25
cytokines and/or chemokines were assessed by using Luminex in serial blood
samples up to 2 weeks after SCI. An analysis of variance was used to determine
the correlations between the phenotypes and the cytokine profiles. RESULTS:
Patient subsets were identified with either M1- or M2-dominant circulating MOs
distinct from the uninjured controls. The M1 dominant was associated with higher
circulating levels of proinflammatory mediators interleukin (IL)12p70 and
interferon gamma-induced protein 10 kDa (IP-10/CXCL10), and lower levels of
anti-inflammatory cytokines IL-10, IL-15, and IL-7, whereas the M2 dominant
exhibited the opposite cytokine profiles with significantly higher IL-10 and
IL-7. CONCLUSION: In the acute phase after SCI, at comparable injury severity,
subgroups of patients exhibit distinct M1 or M2 MOs dominance and the phenotype
is correlated with M1- or M2-specific cytokine and/or chemokine profiles.
Although further studies are needed to determine how these observed phenotypic
differences relate to functional recovery, our findings (1) provide the first
evidence, to our knowledge, that indicates the possible individual differences in
the immune responses to the comparable traumatic SCI, with potential implications
for management of acute SCI and rehabilitation; and (2) may represent easily
accessible biomarkers with prognostic utility.
CI - Copyright (c) 2014 American Academy of Physical Medicine and Rehabilitation.
Published by Elsevier Inc. All rights reserved.

Langue : ANGLAIS